Heartland Dairy
Pasteurizer Documentation & Compliance
FDA-regulated HTST pasteurizer with undocumented CIP sequences. The original integrator retired three years ago. The state inspector is asking questions nobody on staff can answer. See how Controls Foundry closes the compliance documentation gap.
Product Temp
162.4°F
Holding Tube Temp
163.1°F
Flow Rate
48.2GPM
Divert Valve
100%
What's Running at This Plant
Two PLC platforms, three critical food safety systems, and a state inspector who wants to see documentation you do not have.
HTST-01 — HTST Pasteurizer
CompactLogix 1769-L33ER
High-temperature short-time pasteurizer with timing pump, divert valve, and holding tube. The program implements the PMO timing law — but nobody can explain the divert logic to the state inspector. Original integrator retired in 2019.
CIP-01 — CIP Skid
MicroLogix 1100
Clean-in-place system with 5-step wash sequence (pre-rinse, caustic, rinse, acid, final rinse). Sequence timing and chemical concentrations are hardcoded in the ladder logic. No written CIP procedure matches what the PLC actually does.
HMG-01 — Homogenizer
PanelView + CompactLogix
Two-stage homogenizer with PanelView HMI displaying pressure and flow. The CompactLogix handles interlock logic between the homogenizer and the pasteurizer — if one trips, the other must respond correctly.
Live Preview
This is what Controls Foundry looks like when monitoring your equipment.
Signal Dashboard
Product Temperature
Holding Tube Temperature
Holding Tube Temp (Redundant)
Product Flow Rate
Steam Valve Position
CIP Solution Temperature
Seal Pressure
Product Line Pressure
Annotated Ladder Logic
System start permissive. The operator presses Start, but the HTST only runs if the safety chain is complete, E-stop is clear, and steam supply is confirmed available from the boiler. Without steam, the pasteurizer cannot reach legal temperature and would only divert product continuously.
Emergency stop handler. Unlatches both the pasteurization system and any active CIP cycle. The divert valve de-energizes to divert position as a fail-safe consequence of System_Running going false — no product can pass forward.
Product temperature PID loop. Modulates the steam control valve position to maintain 161 deg F at the heater outlet. The PID only runs while the system is in pasteurization mode. Steam valve fails closed on loss of signal (fail-safe).
Redundant RTD cross-check. The deviation between the primary and redundant holding tube RTDs is calculated. If the two sensors disagree by more than 1 deg F, one has drifted or failed. The system cannot trust the temperature reading and must divert.
and 10 more rungs annotated...
HMI Process View
How Controls Foundry Works
From undocumented pasteurizer to FDA-ready documentation package — in three steps.
Upload & Parse
Upload the CompactLogix L5X export and the MicroLogix RSS file. Controls Foundry parses both formats and maps the complete pasteurization and CIP logic.
Auto-detects L5X, RSS, and MicroLogix formats.
Document & Annotate
AI-annotated rung descriptions explain the PMO timing law implementation, divert valve logic, CIP sequence steps, and interlock conditions in plain English — ready for your FDA inspector.
Generates compliance-ready documentation from live program logic.
Plan Migration
Map the MicroLogix CIP program to new CompactLogix hardware, consolidate both systems onto one platform, and extract behavioral test cases to prove the new system matches the old.
Side-by-side comparison ensures nothing changes during migration.
Related Reading
PLC Documentation for Food Safety Compliance
FDA/FSMA documentation requirements, undocumented CIP risks, and how PLC logic proves HTST compliance.
Read moreUnderstanding L5X Files
Everything you need to know about Rockwell's L5X export format — structure, tags, programs, and parsing.
Read moreHow to Read an SLC-500 Without RSLogix
Extract and document your SLC-500 programs using modern tools — no Rockwell license required.
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